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1.
Polymers (Basel) ; 12(11)2020 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-33114527

RESUMO

The development of high-complexity geometry parts is one of the main goals of additive manufacturing technology. However, the failure of printed structures and the joining of different parts to create complex assemblies represents a real challenge in the research of efficient and sustainability techniques for the permanent assembly of polymers. Laser welding processes have been used as a single-step method to join metals for years. Nowadays, the growing trend in the use of thermoplastics for additive manufacturing has led to the need to adapt this technique to materials with a very specific nature and which are more sensitive to thermal effects. In addition, the possibility of transmitting the laser beam through transparent polymer layers allows to us focus the energy supply on internal sections of the assembled components. In this research, an infrared laser marking system was used to join two different samples of polylactic acid manufactured by fused deposited modeling technology. In order to increase the effectiveness of the bonding process, a transparent and a dark sample have been used as assembly material, focusing the laser beam on the interface area of the two parts. By means of tensile tests, dimensional measurement and the use of optical microscopy techniques, a basis was established that links the supplied energy by laser to the joining performance.

2.
Biomed Res Int ; 2018: 5252891, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29984236

RESUMO

Antimicrobial peptides (AMPs) are gaining interest as potential therapeutic agents. Peptides derived from bovine lactoferricin B (LfcinB) have been reported to exhibit antimicrobial activity, and the LfcinB RRWQWR sequence is the smallest known motif that exhibits antibacterial and cytotoxic activity. Our goal was to examine the effect of multicopy arrangements of the RRWQWR motif, on its antibacterial activity against healthcare-associated infections (HCAIs). Linear and branched peptides containing the RRWQWR motif were generated using solid phase peptide synthesis-Fmoc/tBu methodology, purified, and characterized using reverse phase-high performance liquid chromatography and matrix-assisted laser desorption/ionization time of flight mass spectrometry. For each peptide, the antibacterial activity against Staphylococcus aureus (ATCC 25923 and 33591 strains) and Klebsiella pneumoniae (ATCC 13883 and 700603 strains) was assessed by measuring the minimum inhibitory and the minimum bactericidal concentrations, in the exponential phase. Cells were observed by scanning electron microscopy, and the hemolytic activity of the peptides was assessed. The overall results demonstrate that, compared to linear analogues, polyvalent presentation of the RRWQWR motif enhances its antibacterial activity against both Gram-negative and Gram-positive bacteria even on resistant strain.


Assuntos
Antibacterianos/farmacologia , Infecção Hospitalar/tratamento farmacológico , Lactoferrina/farmacologia , Peptídeos/farmacologia , Sequência de Aminoácidos , Animais , Bovinos , Testes de Sensibilidade Microbiana
3.
Psychiatry Res ; 250: 25-29, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28135644

RESUMO

Metacognitive theory of emotional disorders (Matthews and Wells, 1994; Wells, 2009) suggests that metacognitive beliefs can play a causal role in the development and maintenance of anxiety symptoms. In this prospective study, we examine the relationships between metacognitive beliefs, perceived stress and anxiety in a non-clinical sample. Participants were 135 undergraduate students who completed a battery of questionnaire at two time points (3- months apart). Results revealed metacognitive beliefs do not predict long-term anxiety independently. However, moderation analyses demonstrated negative beliefs about uncontrollability and danger prospectively moderated the relationship between perceived stress and Time 2 anxiety. Negative metacognitive beliefs also interacted with baseline anxiety to predict the change in anxiety symptoms. The results confirm metacognitions play a causal role in anxiety and have implications for cognitive models and the treatment of anxiety.


Assuntos
Transtornos de Ansiedade/psicologia , Ansiedade/psicologia , Metacognição , Estresse Psicológico/psicologia , Adulto , Feminino , Humanos , Masculino , Percepção , Estudos Prospectivos , Inquéritos e Questionários , Adulto Jovem
4.
Psicothema ; 28(1): 96-101, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26820431

RESUMO

BACKGROUND:  The Displaced Aggression Questionnaire (DAQ) is an instrument that assesses personality differences in the tendency to displace aggression. This scale is composed of three factors: angry rumination (as affective dimension), revenge planning (as cognitive dimension), and general tendency to engage in displaced aggression (as a behavioral dimension). The present study examined the validity and reliability of the Spanish version of the DAQ.  METHOD: The sample consisted of 429 student and non-student participants. RESULTS: The results showed good psychometric properties, and factor analyses revealed a clear three-factor structure. Further, preliminary data about associations between DAQ scores and indirect aggression and emotion regulation strategies are shown. CONCLUSIONS: The scale presents adequate evidence for potential use in a Spanish population. We discuss its utility for research on different types of aggression (e.g., domestic abuse).


Assuntos
Agressão , Psicometria , Inquéritos e Questionários , Análise Fatorial , Humanos , Idioma , Reprodutibilidade dos Testes , Espanha
5.
J Adolesc ; 37(4): 461-72, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24793394

RESUMO

The study of emotional intelligence (EI) and its association with psychological maladjustment in adolescence is a new and active area of research. However, the diverse range of EI measurements and aspects of psychological maladjustment examined make it difficult to synthesize the findings and apply them to practice. Therefore, we conducted a systematic review to summarize the relationship between EI and adolescents' emotional problems, eating disorder symptoms, addictions, and maladaptive coping. Using English and Spanish keywords, we identified 32 studies that found a negative association between EI and internalizing problems, depression, and anxiety. EI was also associated with less substance abuse and with better coping strategies. These associations differed slightly depending on whether EI was evaluated based on self-reporting or by testing maximum performance. We highlight methodological limitations in the literature on EI and adolescence, and we discuss potentially important areas for future research.


Assuntos
Adaptação Psicológica , Inteligência Emocional , Adolescente , Feminino , Humanos , Masculino , Transtornos Mentais/psicologia , Psicologia do Adolescente
6.
Clin Toxicol (Phila) ; 51(4): 216-24, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23547745

RESUMO

CONTEXT: Sulfur mustard is a blister agent that can cause death by pulmonary damage. There is currently no effective treatment. N-acetyl-L-cysteine (NAC) has mucolytic and antioxidant actions and is an important pre-cursor of cellular glutathione synthesis. These actions may have potential to reduce mustard-induced lung injury. OBJECTIVE: Evaluate the effect of nebulised NAC as a post-exposure treatment for inhaled sulfur mustard in a large animal model. MATERIALS AND METHODS: Fourteen anesthetized, surgically prepared pigs were exposed to sulfur mustard vapor (100 µg.kg⁻¹), 10 min) and monitored, spontaneously breathing, to 12 h. Control animals had no further intervention (n = 6). Animals in the treatment group were administered multiple inhaled doses of NAC (1 ml of 200 mg.ml⁻¹ Mucomyst™ at + 30 min, 2, 4, 6, 8, and 10 h post-exposure, n = 8). Cardiovascular and respiratory parameters were recorded. Arterial blood was collected for blood gas analysis while blood and bronchoalveolar lavage fluid were collected for hematology and inflammatory cell analysis. Urine was collected to detect a sulfur mustard breakdown product. Lung tissue samples were taken for histopathological and post-experimental analyses. RESULTS: Five of six sulfur mustard-exposed animals survived to 12 h. Arterial blood oxygenation (PaO2) and saturation levels were significantly decreased at 12 h. Arterial blood carbon dioxide (PaCO2) significantly increased, and arterial blood pH and bicarbonate (HCO3⁻) significantly decreased at 12 h. Shunt fraction was significantly increased at 12 h. In the NAC-treated group all animals survived to 12 h (n = 8). There was significantly improved arterial blood oxygen saturation, HCO3⁻ levels, and shunt fraction compared to those of the sulfur mustard controls. There were significantly fewer neutrophils and lower concentrations of protein in lavage compared to sulfur mustard controls. DISCUSSION: NAC's mucolytic and antioxidant properties may be responsible for the beneficial effects seen, improving clinically relevant physiological indices affected by sulfur mustard exposure. CONCLUSION: Beneficial effects of nebulized NAC were apparent following inhaled sulfur mustard exposure. Further therapeutic benefit may result from a combination therapy approach.


Assuntos
Acetilcisteína/uso terapêutico , Antioxidantes/uso terapêutico , Substâncias para a Guerra Química/toxicidade , Modelos Animais de Doenças , Intoxicação por Gás/tratamento farmacológico , Pulmão/efeitos dos fármacos , Gás de Mostarda/toxicidade , Acetilcisteína/administração & dosagem , Acetilcisteína/efeitos adversos , Administração por Inalação , Aerossóis , Animais , Antídotos/administração & dosagem , Antídotos/efeitos adversos , Antídotos/uso terapêutico , Antioxidantes/administração & dosagem , Antioxidantes/efeitos adversos , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/imunologia , Substâncias para a Guerra Química/análise , Substâncias para a Guerra Química/farmacocinética , Expectorantes/administração & dosagem , Expectorantes/efeitos adversos , Expectorantes/uso terapêutico , Feminino , Intoxicação por Gás/imunologia , Intoxicação por Gás/patologia , Intoxicação por Gás/fisiopatologia , Pulmão/imunologia , Pulmão/patologia , Pulmão/fisiopatologia , Pneumopatias/etiologia , Pneumopatias/prevenção & controle , Gás de Mostarda/administração & dosagem , Gás de Mostarda/análise , Gás de Mostarda/farmacocinética , Infiltração de Neutrófilos/efeitos dos fármacos , Distribuição Aleatória , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/prevenção & controle , Análise de Sobrevida , Sus scrofa
7.
Water Sci Technol ; 67(3): 514-20, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23202554

RESUMO

Lemon growing areas in the north of Argentina have industries that produce concentrated juice, peel and essential oil and generate a significant amount of liquid and solid waste as lemon pulp. In Argentina, despite the potential applications that the pulp has as animal feed and human and industrial raw material, only 10% is used for these purposes and the rest is discarded into the environment causing many ecological and economic problems. There is little information in the literature on biotechnologies for the treatment of this industrial waste. This paper shows that lemon pulp is a suitable substrate to be treated by anaerobic digestion. We obtained 86 and 92% reduction of chemical oxygen demand in a digester with a semi-continuous feed and retention time of 10 and 20 days respectively and a productivity of 0.406 g CH(4)/g VS h. Comparative tests showed that pre-digesting the pulp improved the process of digestion and increased biogas generation by 20%.


Assuntos
Biocombustíveis , Reatores Biológicos , Citrus/metabolismo , Metano/metabolismo , Anaerobiose , Poluição Ambiental/prevenção & controle , Frutas/metabolismo
8.
J Psychiatr Res ; 45(10): 1395-403, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21683961

RESUMO

BACKGROUND: Few longitudinal studies have examined the trajectory of and the risk factors for depression in a representative sample of the population exposed to terrorism. A 12 month prospective study was conducted among a sample of Madrid city residents after the March 11, 2004 terrorist attacks. We aimed to document the trajectories of depressive symptoms and determine the risk factors associated with these trajectories. METHODS: We conducted telephone surveys among a representative sample of Madrid citizens (N = 1589) to recruit baseline respondents approximately 1 month after the March 11 terrorist attacks. Participants were re-contacted at 6 and 12 months after baseline for further telephone interviews. RESULTS: Findings reveal heterogeneity in the longitudinal trajectories of depression ranging from the absence of depressive symptoms over time, to transient or chronic depression. Life and recent stressors, experiencing direct exposure to the attacks, personality traits, poor physical health and other psychological disorders were principally associated with a worse trajectory of depression after this event. CONCLUSIONS: Consistent with a stress diathesis model, ongoing stressors and intense event exposure are key drivers of a chronic depression trajectory after a mass traumatic event.


Assuntos
Depressão/psicologia , Transtornos de Estresse Pós-Traumáticos/psicologia , Estresse Psicológico/psicologia , Terrorismo , Adulto , Feminino , Humanos , Masculino , Estudos Prospectivos , Fatores de Risco , Espanha/epidemiologia , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Inquéritos e Questionários , Fatores de Tempo
9.
An Pediatr (Barc) ; 73(5): 268-71, 2010 Nov.
Artigo em Espanhol | MEDLINE | ID: mdl-20678974

RESUMO

The classic treatment of Kawasaki disease with immunoglobulin and acetyl salicylic acid obtains a good response in 90% of patients, decreasing the risk of coronary involvement. However, in patients that do not respond to immunoglobulin, it is not clear which therapy should be used: other doses of immunoglobulin, corticosteroids or infliximab. Infliximab is becoming an important second line treatment for Kawasaki refractory to immunoglobulin, although there are few studies and clinical reports with this drug. We present a 5 months-old infant with refractory Kawasaki disease who developed coronary aneurysms despite two immunoglobulin doses and three intravenous pulses-doses of corticosteroids. The infant was finally treated with a single dose of infliximab with good clinical progress.


Assuntos
Anti-Inflamatórios/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Aneurisma Coronário/complicações , Síndrome de Linfonodos Mucocutâneos/complicações , Síndrome de Linfonodos Mucocutâneos/tratamento farmacológico , Humanos , Lactente , Infliximab , Masculino
10.
Vet Pathol ; 38(3): 343-6, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11355669

RESUMO

Intestinal samples and/or lymph nodes of two Iberian pigs from two different farms were submitted for histopathologic examination. Both pigs had proliferation of ileal and/or cecal crypts with almost complete absence of goblet cells. Infection by Lawsonia intracellularis was demonstrated by immunohistochemistry and polymerase chain reaction assay. The mesenteric lymph node of one pig had moderate lymphocyte depletion with granulomatous inflammation of the lymph node parenchyma. Histiocytes and multinucleated giant cells from the lymph node of one pig contained L. intracellularis antigen within the cytoplasm. This pig had also porcine circovirus type 2 (PCV-2) infection, but nucleic acid and antigen of this virus were not demonstrated in the lymph node. The second pig had lymphocyte depletion and marked granulomatous inflammation in Peyer's patches. Histiocytes and multinucleated giant cells in areas of granulomatous inflammation contained L. intracellularis antigen; no PCV-2 nucleic acid or antigen was detected in the tissues of this pig. This is the first description of granulomatous ileitis and lymphadenitis associated with L. intracellularis infection.


Assuntos
Doença de Crohn/veterinária , Surtos de Doenças/veterinária , Infecções por Bactérias Gram-Negativas/veterinária , Lawsonia (Bactéria)/isolamento & purificação , Linfadenite/veterinária , Doenças dos Suínos/microbiologia , Animais , Doença de Crohn/microbiologia , Doença de Crohn/patologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/patologia , Imuno-Histoquímica/veterinária , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Lawsonia (Bactéria)/química , Lawsonia (Bactéria)/genética , Linfonodos/microbiologia , Linfonodos/patologia , Linfadenite/microbiologia , Linfadenite/patologia , Nódulos Linfáticos Agregados/microbiologia , Nódulos Linfáticos Agregados/patologia , Reação em Cadeia da Polimerase/veterinária , Espanha/epidemiologia , Suínos , Doenças dos Suínos/patologia
11.
Acta Microbiol Immunol Hung ; 47(1): 53-61, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10735190

RESUMO

The effect of storing farmhouse ewe cheese in oil and in vacuo over long periods of time on physicochemical properties (water activity and pH) and the microbiota of the cheese was investigated. The storage conditions were found to scarcely influence the sample pH. Also, the initial water activity (a(w) = 0.961) and its value after 9 months of storage (0.927) were both very similar to those for naturally ripened cheese. The incidence of pathogenic microbial groups was found to decrease with storage time (counts fell below 1 log CFU/g). The flora that effects proteolytic changes in cheese consisted of lactic microorganisms (viz. lactococci and lactobacilli), in addition, after 6 months of storage, of enterococci. The last are responsible for the formation of large amounts of soluble nitrogen (SN), non-protein nitrogen (NPN) and aminoacid nitrogen (NH2-N), which provide this type of cheese with very special sensory features while preventing dehydration and thus lengthening its shelf life.


Assuntos
Queijo/microbiologia , Manipulação de Alimentos , Conservação de Alimentos , Óleos de Plantas , Ovinos , Animais , Bactérias/isolamento & purificação , Contagem de Colônia Microbiana , Fungos/isolamento & purificação , Concentração de Íons de Hidrogênio , Azeite de Oliva
12.
J Agric Food Chem ; 48(2): 451-6, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10691655

RESUMO

The chemical and microbial characteristics as well as the flavor and aroma of Los Pedroches cheese made using aqueous extracts of Cynara cardunculus L. flowers were compared with those of cheeses manufactured with extracts of Cynara humilis L. throughout ripening. The two thistle species assayed were found to have no appreciable effect on the moisture, fat, protein, and NaCl contents of the cheese or on its water activity, flavor, and aroma; however, the use of C. humilis resulted in reduced lactic acid content (p < 0.001) and higher pH values (p < 0.05) relative to those of cheese specimens produced with C. cardunculus. The protein breakdown of the cheeses was assessed in terms of soluble nitrogen (SN), nonprotein nitrogen (NPN), and amino acid nitrogen (AAN). Proteolysis was more marked and rapid in cheese containing C. cardunculus as coagulant, the SN and NPN contents of which were significantly higher (p < 0. 01) than those of the cheese obtained with the species C. humilis; AAN contents were similar in both species of Cynara throughout ripening. Although total viable, coliform, and lactobacilli counts were similar in cheeses produced with both types of plant coagulant throughout ripening, enterobacteria and yeasts counts (p < 0.01) and molds counts (p < 0.05) were higher in cheese produced with C. humilis than in cheese obtained with C. cardunculus.


Assuntos
Asteraceae/química , Queijo/análise , Coagulantes/química , Leite/química , Ovinos , Animais , Endopeptidases/isolamento & purificação , Análise de Alimentos , Manipulação de Alimentos/métodos , Extratos Vegetais/química
13.
Zentralbl Veterinarmed B ; 46(6): 375-80, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10481620

RESUMO

This paper concerns a disease affecting a group of African grey parrots, which involves intranuclear inclusion bodies composed of filamentous material. The disease was characterized by either sudden death or death within 2-3 days from onset of non-specific symptoms. At necropsy, gross lesions included enlarged liver, mild hepatic congestion and focal necrosis. Samples from five birds were fixed in 10% formol and routinely processed for light and electron microscopy. In four birds, numerous hepatocytes displayed an enlarged nucleus, with peripheral margination of chromatin; the nucleus was partially or wholly filled by a basophilic inclusion body. In the remaining bird, inclusion bodies were acidophilic and completely filled the nucleus; nuclear enlargement was less evident than in the other birds. At ultrastructural examination, and in both types of IIB, nuclei contained looped filaments but no evidence of viral structures. However, virion-like structures were observed in the cytoplasm of some hepatocytes.


Assuntos
Doenças das Aves/virologia , Hepatite Animal/virologia , Corpos de Inclusão/ultraestrutura , Papagaios , Animais , Doenças das Aves/epidemiologia , Doenças das Aves/patologia , Surtos de Doenças/veterinária , Infecções por Escherichia coli/patologia , Infecções por Escherichia coli/veterinária , Hepatite Animal/epidemiologia , Hepatite Animal/patologia , Rim/patologia , Rim/ultraestrutura , Fígado/patologia , Fígado/ultraestrutura , Microscopia Eletrônica/veterinária , Infecções por Pasteurella/patologia , Infecções por Pasteurella/veterinária , Vírion/ultraestrutura
14.
Acta Orthop Scand ; 69(5): 493-7, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9855231

RESUMO

We treated 167 diaphyseal tibial fractures without reaming and with intramedullary fixation, using an unlocked Küntscher nail. The patients were followed for a minimum of 2 years. The mean time to union was 16 weeks. There were no serious complications, but 1 case of nonunion, 1 case of deep infection and 2 cases of clinically relevant malalignment. Migration of the nail was observed in 11 cases. We conclude that this treatment is simple and gives satisfactory results in diaphyseal fractures after low- or mid-energy trauma.


Assuntos
Pinos Ortopédicos/normas , Braquetes/normas , Fixação Intramedular de Fraturas/métodos , Fraturas da Tíbia/cirurgia , Adolescente , Adulto , Idoso , Pinos Ortopédicos/efeitos adversos , Feminino , Seguimentos , Fixação Intramedular de Fraturas/efeitos adversos , Fixação Intramedular de Fraturas/instrumentação , Consolidação da Fratura , Fraturas Mal-Unidas/etiologia , Fraturas não Consolidadas/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Falha de Prótese , Radiografia , Infecção da Ferida Cirúrgica/etiologia , Fraturas da Tíbia/diagnóstico por imagem , Fatores de Tempo , Resultado do Tratamento
15.
Acta Microbiol Immunol Hung ; 44(2): 155-64, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9330664

RESUMO

The effect of exposure of different pet feed samples to the typical temperature and moisture conditions of many months of the year (9 degrees C and 80% RH) on water activity (aw), pH and growth of various microbial groups (mesophilic aerobic bacteria, fungi and yeasts) was studied. The storage conditions were found to scarcely influence the samples pH, with no significant changes relative to the initial values (the standard deviation was 0.04 and the coefficient of variation 0.85%). By effect of exposure to the temperature and moisture conditions tested, the initially stable feeds reached moisture contents close to 20% and aw values near those of equilibrium with the ambient relative humidity during storage. Microbial counts increased with increasing aw, with final means of 8.44, 9.16 and 8.71 log CFU/g for mesophilic aerobic bacteria, fungi and yeasts, respectively. The risk of mycotoxin production at these aw values is discussed. Careful control of moisture is recommended in order to preserve the quality of pet feed throughout its scheduled shelf life.


Assuntos
Ração Animal/microbiologia , Animais Domésticos , Bactérias/isolamento & purificação , Fungos/isolamento & purificação , Animais , Concentração de Íons de Hidrogênio , Água
16.
Nutr Hosp ; 11(2): 136-40, 1996.
Artigo em Espanhol | MEDLINE | ID: mdl-8695710

RESUMO

One of the clearest indications for enteral nutrition is made up by patients who underwent treatment for orofacial pathology. In this way, we have reviewed retrospectively, 321 clinical histories of patients who underwent treatment (orofacial surgery), dividing these according to the pathology; neoplasia or non-neoplasia (173/148), with enteral nutrition 24 hours after the intervention. Data are collected with regard to the tolerance (vomiting, diarrhea), time needed to reach 1.500 kcal/day, need of parenteral nutritional support, transferrin, prealbumin, and albumin quantification at the start of the nutritional therapy, as well as the total duration there of. Globally, the good enteric tolerance of both groups of patients is noted, despite the fact that the oncological group showed a greater degree of protein malnutrition (statistically significant). As for the total duration of the nutrition, this is greater in the neoplasias, probably due to a more aggressive surgery. The results obtained permit modification of the basic enteral nutrition protocol (reduction of the time used to reach the maximum volume), as well as stressing the preoperative and postoperative regulated nutritional evaluation.


Assuntos
Nutrição Enteral/estatística & dados numéricos , Cirurgia Bucal , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Criança , Pré-Escolar , Nutrição Enteral/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Espanha , Estatísticas não Paramétricas , Cirurgia Bucal/estatística & dados numéricos
17.
Meat Sci ; 38(2): 341-6, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-22059670

RESUMO

On the basis of considering foods with water activity from 0·600 to 0·910 to be intermediate-moisture foods (IMF), we determined the water activity, pH, and some chemical parameters for 70 samples from 17 different selected types of Spanish intermediate-moisture meat products. Even though the salt content is the main water-activity depressor, the sodium chloride molality in the overall amount of water of the product cannot be used to calculate the a(w) value of these types of meat products of intermediate moisture.

18.
Plant Physiol ; 95(4): 1174-80, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16668108

RESUMO

Zea mays L. cv INRA 5a coleoptile segments ecidify the incubation medium on the addition of 1-naphthyl acetate (1-NA). The buffering capacity of the bathing solution increases during 1-NA stimulated medium acidification. The solution bathing the 1-NA treated coleoptile segment was analyzed by high performance liquid chromatography. A considerable amount of acetic acid was detected in the bathing solution used to measure 1-NA-dependent medium acidification. For the first time, the data demonstrate directly the release of acetic acid from 1-NA. The extent of medium acidification was proportional to 1-NA concentration. Simultaneous measurement of medium acidification and acetate content upon addition of 1-NA showed that both processes were temporally correlated. The stoichiometry of proton equivalents to acetate ion was 0.966. Addition of 50 micromolar N,N'-dicyclohexylcarbodiimide had little effect on 1-NA-dependent medium acidification. The results indicate that 1-NA is hydrolyzed in the extracellular space of coleoptile cells.

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